Series filters size

I would like to know the thread size and pitch (in mm) of the
Series VI and VII filters retainer ring. I'm trying to reduce the
number of filters sizes standardizing on E60 and E 55, if
possible.
Thank you all
Alex

Answers

I am not 100% positive that all lenses using these series sizes take
the same retaining ring; however: the series VI ring on the 1st
version 50/2 accepts E44 (an odd size but can be found). I found a
43.5 step-up ring that fits, too, it must be a little oversized. The
serie VI as found on the 90/2 and 90/2.8 and 135/2.8 are E54. Last I
looked B&H have 54-55 step-up rings.